| 1 | interface ThreadSearchTextPart { |
| 2 | readonly text: string; |
| 3 | readonly highlighted: boolean; |
| 4 | readonly start: number; |
| 5 | } |
| 6 | |
| 7 | function foldThreadSearchCase(text: string): string { |
| 8 | const lowered = text.toLowerCase().replace(/ς/g, "σ"); |
| 9 | if (lowered.length === text.length) return lowered; |
| 10 | |
| 11 | let folded = ""; |
| 12 | for (const character of text) { |
| 13 | const loweredCharacter = character.toLowerCase().replace(/ς/g, "σ"); |
| 14 | folded += loweredCharacter.length === character.length ? loweredCharacter : character; |
| 15 | } |
| 16 | return folded; |
| 17 | } |
| 18 | |
| 19 | function scanThreadSearchOccurrences(text: string, query: string, offsets?: number[]): number { |
| 20 | if (text.length === 0 || query.length === 0) return 0; |
| 21 | |
| 22 | const foldedText = foldThreadSearchCase(text); |
| 23 | const foldedQuery = foldThreadSearchCase(query); |
| 24 | let count = 0; |
| 25 | let cursor = 0; |
| 26 | |
| 27 | while (cursor <= foldedText.length - foldedQuery.length) { |
| 28 | const offset = foldedText.indexOf(foldedQuery, cursor); |
| 29 | if (offset === -1) break; |
| 30 | offsets?.push(offset); |
| 31 | count += 1; |
| 32 | cursor = offset + foldedQuery.length; |
| 33 | } |
| 34 | return count; |
| 35 | } |
| 36 | |
| 37 | export function countThreadSearchOccurrences(text: string, query: string): number { |
| 38 | return scanThreadSearchOccurrences(text, query); |
| 39 | } |
| 40 | |
| 41 | export function findThreadSearchOccurrences(text: string, query: string): number[] { |
| 42 | const offsets: number[] = []; |
| 43 | scanThreadSearchOccurrences(text, query, offsets); |
| 44 | return offsets; |
| 45 | } |
| 46 | |
| 47 | export function splitThreadSearchText(text: string, query: string): ThreadSearchTextPart[] { |
| 48 | const normalizedQuery = query.trim(); |
| 49 | if (normalizedQuery.length === 0) { |
| 50 | return [{ text, highlighted: false, start: 0 }]; |
| 51 | } |
| 52 | |
| 53 | const parts: ThreadSearchTextPart[] = []; |
| 54 | let cursor = 0; |
| 55 | for (const offset of findThreadSearchOccurrences(text, normalizedQuery)) { |
| 56 | if (offset > cursor) { |
| 57 | parts.push({ text: text.slice(cursor, offset), highlighted: false, start: cursor }); |
| 58 | } |
| 59 | parts.push({ |
| 60 | text: text.slice(offset, offset + normalizedQuery.length), |
| 61 | highlighted: true, |
| 62 | start: offset, |
| 63 | }); |
| 64 | cursor = offset + normalizedQuery.length; |
| 65 | } |
| 66 | if (cursor < text.length) { |
| 67 | parts.push({ text: text.slice(cursor), highlighted: false, start: cursor }); |
| 68 | } |
| 69 | return parts; |
| 70 | } |